plz help me with PIC18f series

Hello to all. Im doing a project to track the 6DOF of an object using analog devices sensors. The sensor o/p r fed to the PIC. I have a few ques. here:

1. I need to find posn. so I need to double integrate acceleration o/p from sensors. How exactly is this to be done?

2. I need to convert the values to digital. I guess I need to first double integrate and then perform A/D else by doing the other way round it would increase the error. I would liek to know if wht Im thinking is right?

Plz help me on this. Im a beginer and having a tough time with PIC.

Thnx in advance for the help.
bye.

Such inertial systems are VERY prone to cumulative velocity and location offset errors due to device offset and ADC/numeric intergrity errors. In general you need to get a position or at least an absolute velocity (wheel tachometers) periodically to correct the error. For example it can be added to a GPS system to provide a more accurate, detailed understanding of your velocity and direction while navigating turns than the periodic GPS coordinates would provide.

I'd think that taking instantaneous readings and doing integration digitally makes more sense. The PIC18F series has a 10 bit ADC. This may not be best for 2 reasons. One, 10 bits may not be enough resolution. Two, accelerometers are differential devices and these 18F ADCs don't do differential directly. It may be simplest to use an external, differential, high resolution ADC.